The present invention relates to a surgical saw blade fastening means and more specifically to a combination of a saw blade and chuck assembly for use on a powered reciprocating surgical instrument.
Prior art surgical saw blades have almost universally consisted of a shank portion and a blade portion formed from separate stock and secured to the shank portion by suitable means such as by brazing. The shank portion of such blades have usually been cylindrical with a flat provided thereon for locking engagement by a set-screw on the surgical instrument into which the shank is inserted. Replacement of such blades, of course, requires that the set-screw be loosened to permit the shank to be withdrawn. Also, discarding of such blades when dulled meant that the shank was also discarded.
U.S. Pat. No. 2,951,482, issued Sept. 6, 1960, discloses a surgical saw blade for a hand saw having a generally rectangularly shaped shank portion which fits into a slotted stem of a chuck and is clamped therein by the action of a threaded collar being threaded onto the bifurcated stem.
U.S. Pat. No. 3,041,724, issued July 3, 1962, relates to a hand extension tool for non-surgical uses and comprises a plurality of elongated tool elements divided by transverse score lines so that when a working surface such as a knife edge has been worn it can be broken off and a new working surface exposed. The upper longitudinal edge of the tool elements is threaded over its entire length and the opposite (lower) longitudinal edge is threaded at spaced locations along its length with working surfaces provided between the threaded portions. The threads are engaged by a nut rotatably mounted within one end of the handle. The tool element is prevented from rotation within the handle by a slotted cylindrical member fixed to the handle.
Although the foregoing patents show that prior workers have not been unaware of the desirability of having a tool wherein blades could be changed without the use of additional tools, so far as is known, no one has addressed the problem as it relates to a powered reciprocating instrument and particularly a surgical instrument for use on living bone and its attendant critical requirements.